The goals of our researh are: (1) to develop theory-guided methods for the assessment of individual differences in child temperament, (2) to investigate the stability (and/or instability) of temperament assessments over time and the extent to which infant temperament may be predictive of later characteristics of young children, (3) to test hypotheses about the ontogenesis of emotions and their interaction with social and personality development, (4) to investigate the origin of sex differences, if any, in temperamental characteristics, (5) to investigate the interaction between infant/child temperament and the parents' development of procedures for controlling and/or influencing the child. To date, we have gathered temperament data on 62 infants seen on eight occasions between 3 and 13 1/2 months of age, with additional questionnaire data at 24 months. The data includes parent report information (the Infant Behavior Questionnaire) as well as videotaped records of infants' reactions to visual, auditory and tactile stimuli designed to elicit emotional, motor, autonomic and attentional reactions. These assessments allow us to observe the basic aspects of temperament, as reflected in motor activity, attentional activity, vocalization, smiling and laughter, fear and frustration. In our infant data, we have now coded videotapes for temperament at 13 1/2 months and developed codes for assessing temperament at earlier ages. We propose in the current granting period to code all videotapes collected at 10, 16 1/2, and 3 months of age (two sessions at each age) and to perform longitudinal and cross-validational analysis on the laboratory and IBQ data. We also propose to develop and administer measures for a follow-up assessment of these children at 5 years of age, investigating aspects of temperament and early personality, with an emphasis on their development of self regulative strategies in relation to their early temperamental characteristics. Parent-child interactions and social control techniques will also be investigated.